Joe Celko's SQL for Smarties, 3rd Edition

Chapter 14. The [NOT] IN() Predicate

THE IN() PREDICATE IS very natural. It takes a value and sees whether that value is in a list of comparable values. Standard SQL allows value expressions in the list, or for you to use a query to construct the list. The syntax is:

<in predicate> ::=
<row value constructor> [NOT] IN <in predicate value>

<in predicate value> ::=
   <table subquery> | (<in value list>)

<in value list> ::=
   <row value expression> { <comma> <row value expression> }...

The expression <row value constructor> NOT IN <in predicate value> has the same effect as NOT (<row value constructor> IN <in predicate value>). This pattern for the use of the keyword NOT is found in most of the other predicates.

The expression <row value constructor> ...